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  <title>AIMD with Decreasing Increases</title>
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<h1 style="direction:ltr;"><b><font color="#808000">AIMD with Decreasing Increases</b></font></h1>
<ul><li style="direction:ltr;"><h2>AIMD</h2></li>
<ul><li style="direction:ltr;"><i><font color="#CC3300">x = x + (x)</i></font>, for every constant interval (e.g., RTT)</li>
<li style="direction:ltr;"><i><font color="#CC3300">x = (1 - ) x</i></font>, when there is a packet loss event</li>
<li style="direction:ltr;">where <i>x</i> is the packet sending rate.</li>
</ul><li style="direction:ltr;"><h2>TCP</h2></li>
<ul><li style="direction:ltr;"><i>(x) </i> <i>1</i>, and the increase interval is RTT<i>.</i></li>
<li style="direction:ltr;"><i> = 0.5</i></li>
</ul><li style="direction:ltr;"><h2>AIMD with Decreasing Increase</h2></li>
<ul><li style="direction:ltr;"><i>(x) </i>is non-increasing, and<i> limx-&gt;+ (x) = 0.</i></li>
</ul></ul><br>
<h3>Notes:</h3>
<p style="direction:ltr;"><font color="#000000">AIMD has many good properties including global stability and its behavior is well understood. The AIMD algorithm can be modeled by an increase function of alpha(x) and a decrease factor of beta.</font></p>
<p style="direction:ltr;"><font color="#000000"></font></p>
<p style="direction:ltr;"><font color="#000000">For example, in TCP, alpha(x) always equal to 1 and beta is 0.5.</font></p>
<p style="direction:ltr;"><font color="#000000"></font></p>
<p style="direction:ltr;"><font color="#000000">UDT uses a special case of AIMD algorithm, in which the increase function alpha(x) is non-increasing, and approaches to zero as x increases.</font></p>
<p style="direction:ltr;"><font color="#000000"></font></p>
<p style="direction:ltr;"><font color="#000000">(x UNIT: packets/sec)</font></p>
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